ci: twister: Use zephyrproject-rtos/action-s3-cache

This commit updates the Twister workflow to use the 'action-s3-cache'
action from the zephyrproject-rtos organisation.

It also updates the action reference such that it uses a specific
version of the action instead of the latest master.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

.github/workflows/twister.yaml

@@ -195,7 +195,7 @@ jobs:
 
       - name: use cache
         id: cache-ccache
-        uses: nashif/action-s3-cache@master
+        uses: zephyrproject-rtos/action-s3-cache@v1
         continue-on-error: true
         with:
           key: ${{ steps.ccache_cache_timestamp.outputs.repo }}-${{ github.ref_name }}-${{github.event_name}}-${{ matrix.subset }}-ccache